ALT-2 Automotive Maintenance Change the Brake Fliud
Why should you change your brake fluid? The short answer is so you can stop your vehicle. Clean brake fluid comes in handy if you want your brakes to work. If that's not a compelling enough reason for you, then read on.
The brake system is pretty basic by design. It works on the principal of action and reaction. When you push the brake pedal, brake fluid is forced through the brake lines. At the other end of the line, the brake fluid pushes a piston, which consequently actuates the brakes. The entire concept is based on the fact that brake fluid does not compress. Or, rather, clean brake fluid does not compress. Dirty brake fluid is another story.
Brake fluid functions in a sealed system, but that in itself provides little protection against heat or everyday wear and tear. It is exposed to heat from the engine, the transmission, and the exhaust system. Furthermore, the stop and go of city driving heats the calipers in the brake pistons, which in turn heats the fluid. When brake fluid gets hot, it breaks down. If it gets hot enough to boil, this releases air into the system.
Normal wear and tear further will complicate things further. Typical wear on internal moving parts produces small amounts of debris. These bits of rust and dirt can cause internal damage to your Antilock Brake System (ABS). Additionally, condensation, typically formed in very small amounts, lets water in.
Water. Air. Dirt. Debris. Rust. All or any one of these contaminates will cause a breakdown in the primary characteristic of brake fluid that makes it work: compression, or rather a lack thereof. Because clean brake fluid does not compress, you can be fairly secure in the knowledge that pressing your brake pedal will push that fluid down the line and functionally apply the brakes. When your brake fluid is compromised by any of these factors, the whole process is much less effective. Simply put, you push harder and get less braking power.
The solution is to flush your brake system, generally every 30,000 miles or with each brake change. The old fluid must be flushed completely-never mix old brake fluid with the new stuff. Because you have to be able to remove all of the air from the system when you're finished, this is not a job for the average do-it-yourselfer. So pull out your wallet and take it somewhere and have it done, because even if you're not convinced of the merits of properly working brakes, those of us on the road around you would appreciate the gesture!
